All you need to know about Film Capacitors

One of the essential discrete components for electrical setup is a capacitor. Their unique electrical properties make them highly useful. You can use them in large assembly electrical units for their excellent recovery properties. 

The main function of the film caps

Capacitors are an electronic component that stores electricity and can release it when required in an electric circuit. It can pass alternate current and simultaneously block direct current. The voltage smoothing capacitors called Film Capacitors are more convenient to use. You can recognize their vehement use in fitters and audio crossovers to store and release high-current plus when required. This high current pulse further helps in generating light discharges or power pulse lasers. 

Application of the component

This electrical component is present in places like phase shifters, X-ray flashes, pulsed lasers, etc. The low-power variant functions as decoupling capacitors, fitters, and converters. Other than these, you can also find their application in fluorescent light ballasts and to suppress electromagnetic interference.  

Manufacturing details

Manufacturing these film caps needs expert hands. Manufactured out of two fragments of plastic film, the Plastic Film Capacitors are dielectric in nature, containing electric capacitors insulated with a plastic film. Each of the plastic films has a layered electrode, usually made of aluminium. This property makes it easy for electrical connections and thus can handle higher current surges.  

Points to keep in mind

While selecting the capacitor for your electrical unit, keep the following in mind. As they contribute to the important attributes like the voltage of the unit, make sure to choose the appropriate variant for your purpose.

Material of the dielectric

The materials used in manufacturing the plastic capacitors largely affect the functionality of the working unit. Depending on the material of the dielectric, their operation and application are classified.

• Polyester: Popularly known as PET or Mylar Film Capacitors, have replaced the old paper capacitors. Due to their low moist absorption, they are apt for DC to use up to 60kV with a temperature less than 125 degrees. 

• Polystyrene: These are the most common, general-purpose capacitors. They are stable like the previously mentioned one and features low moist absorbing quality. These are better to apply with low power radio frequencies with their temperature limited to 85 degrees. 

• Polycarbonate: Polycarbonate ones are the thermoplastic polymers, also known by the trademarked names. They feature a higher quantity of insulation resistance and a good dissipation ratio. These have comparatively better dielectric absorption than polystyrene film caps.

• Polypropylene: This kind of capacitor is extremely strong and highly reliable. For this, they are found in power applications having high voltage and frequency. They are, in general, more susceptible to damage resulting from power surges or pulses. 

Overview

The Electronics Industries Alliance (EIA) has set specific standards related to the capacitors to denote their application reliability in different devices or setups. Make sure to choose the appropriate one that is fit for the power of your setup.